delta drag
AQ500,
You're right, everything else being equal, higher aspect ratio gives lower induced drag. In this case, the stated objective is high speed, with no concern about maneuvering. The high-speed, level flight situation is a low-lift scenario. Induced drag is a big problem when high lift is generated, as in the hard turns of pylon racing. For a high-speed pass, there is no concern with lift, as there will be plenty. The cruise missile comparison is not especially valid perhaps, since the Tomahawk acually has a fairly high aspect ratio, probably to maximize range. I think the more important design issue is getting enough lift for take off and landing. If you are willing to launch the way people are launching Diamond Dust, then takeoff is not an issue. I don't know how people land the Diamond Dust, but in principle, the delta wing could generate pretty decent lift at high angle of attack, allowing a reasonable landing speed. You couldn't do that with a typical high aspect ratio wing, but you might be able to with a low aspect ratio wing, possibly using a leading edge extension and some leading edge sweep, like the F-18. If you just don't need to worry about landing, I agree, a highly loaded, high aspect ratio wing would be even lower drag, although a little tougher to build with enough strength.
Banktoturn